Plug-in connector comprising a secondary locking mechanism impinged by a spring

ABSTRACT

The invention relates to a plug-in connector ( 1 ), in particular for airbag retaining systems, comprising a first housing ( 2, 3 ), which can be locked into a mating connector ( 7 ) by means of locking arms ( 4   a   , 4   b ) and a secondary locking mechanism ( 5 ) that can be impinged by a spring force. Said secondary locking mechanism ( 5 ) has tongues ( 6   a   , 6   b ), which block the locking arms ( 4   a   , 4   b ) once the latter have engaged in the mating connector ( 7 ), in addition to detent arms ( 8   a   , 8   b ), which are blocked by the introduction of one edge ( 9 ) of the mating connector ( 7 ) until the locking arms ( 4   a   , 4   b ) are engaged and which then slide off the edge ( 9 ) as a result of the spring force that has accumulated up to this point, pressing the secondary locking mechanism ( 5 ) into its final position.

The present invention concerns a plug-in connector, in particular forairbag retaining systems according to the preamble of patent claim 1.Such a plug-in connector is known from DE 100 35,726 A1.

In several respects, stringent requirements are placed on such plug-inconnectors relative to the reliability of the connection that isproduced and of the plugging-in process of a plug-in connector into itsmating connector. In addition, the plug-in connection must be designedfor a very long service life, during which fatigue phenomena of theseating of the plug must not occur.

A plug-in connector with a secondary locking mechanism is known fromEP-1,207,591 A2, in which, during the plugging-in process of theconnector into a corresponding mating connector and after the engagingof a primary locking mechanism, a secondary locking mechanism is movedinto a slot between a tongue of the primary locking mechanism and theconnector housing, in order to fill this slot and to prevent the primarylocking mechanism from popping out of its locked position. In this case,the tongue of the secondary locking mechanism is continually underelastic strain in the final state, so that it may become subject tomaterial fatigue, and, as the case may be, to material fracture over thelong term. If pieces of the tongue of the secondary locking mechanismfall out of the slot, the secondary locking would therefore no longer besecure. At the very least, the correct seating of the plug-in connectorin its mating connector would no longer be secure.

An electrical connector is known from DE 196 20,177 A1, in which anelectrical contact between complementary connectors is first made towardthe end of the plugging-in process in such a way that, during theplugging-in process, a spring is tensed, which moves the connectors intoone another when a predetermined spring force has been exceeded andafter release of its spring excursion.

DE 198 47,872 A1 describes an ignition bus housing with a secondarylocking mechanism, which is pre-tensed by a spring during theplugging-in process and after engaging of the connector lockingmechanism, moves by spring force over the connector lock and blocks itin its locking position.

In DE 100 05,858 A1, a spring clip acting as a safety device providesfor the circumstance that the secondary locking can only take place whenthe connection of the connector has been concluded.

DE 100 35,726 A1 shows a contact support, in which a secondary lockingmechanism is held back during the plugging-in process until the lockingmechanism has been engaged. A spring tension is built up during theplugging-in process, and when this is released it moves the secondarylocking mechanism into its final position. This release takes placeafter the spring tension has become large enough, due to the compressionof the spring, in order to overcome an elastic resistance, which isformed by an elastic compressible clamp. The behavior of the latterdetermines the time point for triggering and this time can thus bedetermined only imprecisely and is hardly reproducible.

A plug-in connector with a secondary locking mechanism is known from EP1,006,621 A1, wherein the secondary locking mechanism rests on one edgeof the mating connector, until it is released by shifting laterally at aspecific stage of the connecting process.

The object of the present invention is to further develop a plug-inconnector of the type named initially in such a way that the secondarylocking mechanism is supported by spring force at a pre-specified momentduring the plugging-in process and is brought into its final position,but essentially rests free of mechanical strain in the final state.

This object is solved according to the claims.

The present invention is based on the concept of building up a springforce during the connecting process, by means of which the secondarylocking mechanism is “catapulted” into its final position after theprimary locking mechanism is engaged, and it then rests with essentiallyrelaxed spring elements.

The spring elements can stand under slight mechanical strain in thefinal state, in order to prevent a chattering in the case of vibrations.The invention will be explained in more detail in the following, basedon the description of an example of embodiment, which is not to beunderstood as limiting, with reference to the drawing.

The following are shown therein:

FIG. 1 an exploded view of the plug-in connector according to theinvention,

FIGS. 2 to 6 the individual steps of the plugging-in process, and

FIG. 7 the unlocking of the plug-in connector from its mating connector.

FIG. 1 shows an exploded view in perspective of the plug-in connector 1according to the invention. The housing is designed of two parts and iscomprised of a housing part 3 on the connector side and a housing part 2on the side turned away from the connector, and these parts are lockedwith each other. The housing part 3 on the connector side has lockingarms 4 a, 4 b, with which the plug-in connector 1 is locked in a matingconnector 7 (FIG. 3). Within housing 2, 3, a secondary locking mechanism5 is found, which has tongues 6 a, 6 b, which, after locking of thelocking arms 4 a, 4 b in the mating connector 7, fill a gap between thebody of the plug-in connector and the locking arms 4 a, 4 b and thusprevent a swinging back of the locking arms 4 a, 4 b out of theirlocking position.

Further, the secondary locking mechanism 5 has detent arms 8 a, 8 b(FIG. 2), which will be explained in more detail in the following, andare formed like a tuning fork in the example of embodiment which isshown, with beveled free ends, on which are found catch pieces pointingoutward. At the beginning of the plugging-in process of the plug-inconnector, the secondary locking mechanism is supported by these freeends in its mating connector 7, supported at the edges of a slot in themating connector. The secondary locking mechanism 5 is attached by meansof four spiral-shaped pressure springs at the back housing part 2 seenin the direction of plugging in, in the example of embodiment shown. Thepressure springs are aligned coaxially to the direction of plugging in.In the state as supplied, i.e., the two housing parts 2, 3 are lockedwith one another, the pressure springs 10 a to 10 d are either almostnot compressed at all or are only very slightly compressed. A slightcompression serves to protect the connector from chattering.

The back housing part 2 has longitudinal slots on opposite-lying sidesin the direction of plugging in, from which project pieces 13 a, 13 b,which are formed on the secondary locking mechanism 5. A detaching aid12 is plugged onto these pieces 13 a, 13 b by means of slot 14 in itsside walls, and this aid surrounds the housing 2, 3 at least partially.This detaching aid can be moved by an operator in the direction oppositethe plugging-in direction against the action of the force of thepressure springs 10 a to 10 d, whereby the locking tongues 6 a, 6 b andthe detent arms 8 a, 8 b can be pulled out of the mating connector andthe plug connection can be detached.

The individual steps of the plugging-in process will be explained in thefollowing on the basis of FIGS. 2 to 6.

FIG. 2 shows the as-supplied state of the plug-in connector, in which,as has already been explained above, the pressure springs 10 a to 10 dare essentially relieved of strain and the free ends 11 a, 11 b of thedetent arms 8 a, 8 b are arranged protected in the connector part ofhousing part 3.

FIG. 3 shows the plug-in connector 1 at the moment in which it is matedwith mating connector 7, i.e., it is put directly in contact with thelatter. The free ends 11 a,11 b of the detent arms 8 a, 8 b in this caselie on the front surface of mating connector 7. In other respects, FIG.3 does not differ from FIG. 2.

The final position of plug-in connector 1 in mating connector 7 is shownin FIG. 4, i.e., the locking arms 4 a, 4 b are engaged behind shoulders,which are not shown here, of mating connector 7. The plugging-in processhas been produced against the spring force of pressure springs 10 a to10 d, which are now all almost completely compressed. In this state, thedetent arms 8 a, 8 b are still continually supported at the edges of thementioned slots in the mating connector 7. This state changes abruptly,right after the detent arms 4 a, 4 b are snapped in.

FIG. 5 shows this state, i.e., a slight pressure loading in theplugging-in direction of the plug-in connector 1 leads to the conditionthat the detent arms 8 a, 8 b are slipped out, pressed away from theedges of the slots in the mating connector 7, by ramps disposed onhousing part 3 and the detent arms 8 a, 8 b are catapulted into the slotby the force of pressure springs 10 a to 10 d, so that the secondarylocking mechanism 5 snaps into its final position, whereby the tongues 6a, 6 b are introduced into the slots behind the detent arms 4 a, 4 b.

FIG. 6 shows this state once more, wherein, however, the free ends 11 a,11 b, which are spread apart from one another, of detent arms 8 a, 8 bare shown, with which the secondary locking mechanism 5 has been lockedin mating connector 7.

FIG. 7 shows the unlocking process, wherein the detaching aid 12 ispulled in the direction opposite the plugging-in direction, against theaction of the pressure springs 10 a to 10 d. In this way, the secondarylocking mechanism 5 is detached from mating connector 7, so that thesecondary locking of locking arms 4 a, 4 b is abolished and anadditional pull on detaching aid 12 pulls the plug-in connector 1 out ofthe mating connector 7.

The plug connection produced in this way allows only unequivocal stateswhich are also clearly perceived by the user. The “shooting in” of thesecondary locking mechanism is clearly perceptible and ends up in aclearly locked state due to the pressure loading. Therefore, the plug-inconnector according to the invention assures an increased security,which is particularly essential for use as an airbag connector.

1. A plug-in connector, in particular for airbag retaining systemscomprising a first housing, which can be locked in a mating connector bymeans of locking arms and a secondary locking mechanism that can beloaded with a spring force, in which the secondary locking mechanism hastongues, which block the locking arms after they are engaged in themating connector, as well as detent arms, which are blocked by one edgeof the mating connector during the introduction process, until thelocking arms are engaged, is hereby characterized in that the lockingarms then slide off the edge due to the spring force that has beenpreviously built up and press the secondary locking mechanism into itsfinal position, wherein the detent arms have beveled catch pieces ontheir free ends.
 2. A plug-in connector, in particular for airbagretaining systems comprising a first housing, which can be locked in amating connector by means of locking arms, and a secondary lockingmechanism that can be loaded with a spring force, in which the secondarylocking mechanism has tongues, which block the locking arms after theyare engaged in the mating connector, as well as detent arms, which areblocked by one edge of the mating connector during the introductionprocess, until the locking arms are engaged, is hereby characterized inthat the locking arms then slide off the edge due to the spring forcethat has been previously built up and press the secondary lockingmechanism into its final position, wherein ramps on a part of the firsthousing move the detent arms away from edge just before the completecompressing of helical springs.
 3. The plug-in connector according toclaim 1, further characterized in that the secondary locking mechanismis supported on housing by means of at least one helical spring, whereinthe helical spring or springs is or are relieved of strain when theplug-in connector is not plugged in as well as when it is plugged in. 4.The plug-in connector according to claim 3, further characterized inthat the detent arms are shaped like a pair of tuning forks with catchpieces protruding outward.
 5. The plug-in connector according to claim2, further characterized in that the housing has a connecting half and aback half, which can be locked with one another and in which thesecondary locking mechanism with helical springs is disposed.
 6. Theplug-in connector according claims 1, further characterized in that thesecondary locking mechanism has pieces running crosswise to theplugging-in direction on opposite-lying sides, and these pieces engagein corresponding slots of a detaching aid surrounding the housing atleast partially, and the secondary locking mechanism can be pulled outof mating connector by this aid against the force of springs and thenthe housing can be detached from mating connector in the state where thesecondary lock is no longer engaged.